The Collaborative Perinatal Project (CPP) is a rich data set for the investigation of a variety of topics related to maternal and child health. Recent projects have also begun to utilize the serum collected from pregnant women and their neonates as part of this study, which, along with data collected as for the original study and subsequently, provides a unique resource. Areas investigated in FY 06 include, time required to become pregnant and adverse outcomes of the pregnancy, maternal serum estrogen and androgen levels and cryptorchidism in male infants, maternal smoking and childhood growth, use of oxygen during neonatal resuscitation and subsequent development of childhood cancer, association between birth marks and childhood cancer in-utero tobacco smoke exposure and subsequent age at menarche, smoking and SGA versus preeclampsia, whether use of aspirin in early pregnancy is associated with the occurrence of spontaneous abortion, and whether markers of restricted fetal growth are associated with blood pressure at age 7.[unreadable] [unreadable] Recent papers have demonstrated that aspirin use in pregnancy is associated with a reduced risk of miscarriage(7), that much of the previous work on the interaction between birthweight and postnatal growth on subsequent blood pressure was not done improperly, failing to take into account that children tracking a higher growth percentile normally gain more absolute weight than those tracking a lower percentile (3). Additional papers have shown that the association between birthweight and subsequent blood pressure is different in African-American than in white populations (6). The latter of of interest, considering that there have been virtually no studies of the "Barker hypothesis" among African-Americans. Other papers have deomnstrated that obese women are more likely to experience dizygous twinning (11), and that maternal serum steroid hormones during pregnancy are not associated with the risk of cryptorchidism among male offspring (9).[unreadable] [unreadable] Pilot work has demonstrated that genomic DNA can be recovered successfully from stored CPP serum, and a study of maternal CYP1A9 polymorphisms and offspring birth defects among women taking phenytoin during pregnancy is underway.